JP2005171794A - Direct injection type fuel injection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suitably set the atomization length, by suitably atomizing fuel in the whole area of an operation condition. <P>SOLUTION: This fuel injection device 3 has a fuel injection valve 43 for injecting the fuel into a combustion chamber 2, and an air injection valve 44 for injecting air; and is provided with one fuel nozzle port 69a opening in the combustion chamber 2 in response to the fuel injection valve 43, and a plurality of air nozzle ports 69b opening in the combustion chamber 2 in response to the air injection valve 44. A shape, the size and the direction of the fuel nozzle port 69a are specified. The number, a shape, the size, the direction of the air nozzle ports 69b and arrangement to the fuel nozzle port 69a are specified. Fuel atomization and an air jet injected into the combustion chamber 2 via the fuel nozzle port 69a and the air nozzle ports 69b from the respective injection valves 43 and 44, collide with each other. A distance up to the air nozzle ports 69b from the fuel nozzle port 69a, is set to a predetermined value of a range of 1 to 4 mm. A collision angle of the fuel atomization and the air jet is set to a predetermined value of a range of 15 to 75°. Fuel pressure supplied to the fuel injection valve 43 is set to 1 to 4 MPa. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a direct injection type fuel injection device that directly injects fuel into a combustion chamber of an internal combustion engine (engine) by colliding fuel injected from a fuel injection valve and gas injected from a gas injection valve.

  Conventionally, for example, Patent Documents 1 and 2 below disclose a fuel injection device configured to collide fuel injected from a fuel injection valve and air injected from an air injection valve.

  In Patent Document 1, in an in-cylinder injection (direct injection) spark ignition engine, the mounting angle of the air injection valve and the fuel injection valve is such that both injection axes intersect in the vertical direction and the horizontal direction, and the injection direction is It is described that both are set to an angle directed to the cavity combustion chamber. With this configuration, since the air injection axis and the fuel injection axis intersect, the fuel can be atomized at the time of fuel intake stroke injection, and since the injected air is directed to the cavity combustion chamber, the fuel adheres to the cavity combustion chamber. Patent Document 1 describes that the generation of smoke and unburned HC can be reduced.

  On the other hand, Patent Document 2 discloses a pair of fuel injection type internal combustion engines, which are not direct injection types, but in which the injection directions intersect each other at positions where the fuel injection ports are sandwiched from both sides on a plane substantially including the fuel injection ports. It is described that the air assist nozzle is arranged. It is described in Patent Document 2 that the fuel flow from the fuel nozzle is narrowed by the air flow from both sides of the fuel nozzle and flattened as a whole.

  Here, in order to obtain optimum combustion performance in a direct injection type engine, it is necessary to promote atomization of fuel in order to improve combustibility throughout the engine operating conditions. In a direct injection engine, the spray penetration distance (distance from the nozzle hole of the fuel injection valve to the spray tip (spray length)) is set in order to obtain combustion performance in accordance with cold start and partial load operation. There is a need.

JP 2000-97032 A (page 5-6, FIG. 10, FIG. 11) Japanese Patent Laid-Open No. 4-50469 (page 2-6, FIG. 2)

  However, in the engine described in Patent Document 1, when stratified combustion (mainly during partial load operation), when a large amount of air corresponding to the intake air amount is injected and collided with fuel, the air-fuel mixture is dispersed. This makes it impossible to stratify the air-fuel mixture necessary for stratified combustion. For this reason, during stratified combustion, fuel atomization by air collision cannot be suitably performed. As a result, optimum combustion performance cannot be obtained during stratified combustion in a direct injection type engine.

  In addition, Patent Documents 1 and 2 described above do not describe anything about the setting of the spray penetration distance (hereinafter referred to as “spray length”). For this reason, in order to obtain the combustion performance in accordance with the cold start of the engine or the partial load operation, the spray length cannot be suitably set, and the combustion performance cannot be improved.

  The present invention has been made in view of the above circumstances, and its object is to achieve direct fuel injection that achieves suitable fuel atomization over the entire operating conditions of the internal combustion engine and allows the spray length to be set appropriately. A fuel injection device is provided.

  In order to achieve the above object, the invention described in claim 1 is a fuel injection valve for injecting fuel into a combustion chamber of an internal combustion engine including an intake valve and an exhaust valve, and also for injecting gas into the combustion chamber. A direct injection type fuel injection device including one gas injection valve, including one fuel injection valve, and provided with one or more fuel injection holes opened in the combustion chamber corresponding to the fuel injection valve Including at least one gas injection valve, provided with one or more gas injection holes opened in the combustion chamber corresponding to the gas injection valve, and the shape, size, and direction of the fuel injection hole That the number, shape, size, direction, and arrangement of the fuel nozzles are specified, and the distance from the center of the fuel nozzle to the center of the gas nozzle is 1 A predetermined value in a range of ˜4 mm, and a fuel It is intended that the fuel injected from the injection valve and injected into the combustion chamber through the fuel injection hole collides with the gas injected from the gas injection valve and injected into the combustion chamber through the gas injection hole. .

  According to the configuration of the above invention, fuel spray is formed in the combustion chamber by injecting the fuel injected from one fuel injection valve into the combustion chamber from the corresponding one or more fuel injection holes. The form of this fuel spray is determined by specifying the shape, size, direction and arrangement of the fuel injection hole. On the other hand, gas injected from at least one gas injection valve is injected into the combustion chamber from the corresponding one or more gas injection holes, thereby forming a gas jet in the combustion chamber. The form of the gas jet and the influence on the fuel spray are determined by specifying the number, shape, size, direction and arrangement of the gas nozzles with respect to the fuel nozzles. Here, the fuel injected from the fuel injection valve and injected into the combustion chamber through the fuel injection hole collides with the gas injected from the gas injection valve and injected into the combustion chamber through the gas injection hole. The fuel spray collides and the fuel spray is atomized. To set the spray length by the gas injected from the gas nozzle, the energy of the gas jet interferes with the fuel spray at the collision point between the fuel spray and the gas jet, and the fuel atomization and spray length are set. Must be retained as much as possible. Here, the energy of the gas jet decreases as the distance from the gas injection hole increases. Therefore, by arranging the gas nozzle in the vicinity of the fuel nozzle, the energy decrease of the gas jet due to the air resistance from the gas nozzle to the fuel spray is reduced, and the collision point between the gas jet and the fuel spray is the fuel jet. The fuel atomization and spray length can be set near the hole. In particular, according to the present invention, since the distance from the center of the fuel nozzle hole to the center of the gas nozzle hole is set to a predetermined value in the range of 1 to 4 mm, the collision point between the gas jet and the fuel spray is the fuel nozzle hole. It is set at an optimal position in the vicinity, and it is possible to increase the atomization of fuel and extend the spray length with a gas jet of the same energy.

  In order to achieve the above object, a second aspect of the present invention provides a fuel injection valve for injecting fuel into a combustion chamber of an internal combustion engine including an intake valve and an exhaust valve, and also for injecting gas into the combustion chamber. A direct injection type fuel injection device including one gas injection valve, including one fuel injection valve, and corresponding to the fuel injection valve, provided with one or more fuel injection holes opened in the combustion chamber. And at least one gas injection valve, corresponding to the gas injection valve, provided with one or more gas injection holes opened in the combustion chamber, and the shape, size, direction and The arrangement is specified, and the number, shape, size, direction and arrangement of the gas injection holes are specified, and the fuel injection holes are injected and injected into the combustion chamber through the fuel injection holes. Fuel injected from the gas injection valve The gas injected into the combustion chamber through the cylinder is caused to collide, and the collision angle between the fuel injected from the fuel nozzle and the gas injected from the gas nozzle is set to a predetermined value in the range of 15 to 75 °. The purpose is to be.

  According to the configuration of the above invention, unlike the invention of claim 1 in particular, the collision angle between the fuel injected from the fuel injection hole and the gas injected from the gas injection hole is a predetermined range of 15 to 75 °. Since it is set to a value, the acting force of the gas jet in the direction of fuel spray becomes large, and the spray length can be extended.

  In order to achieve the above object, a third aspect of the present invention provides a fuel injection valve for injecting fuel into a combustion chamber of an internal combustion engine including an intake valve and an exhaust valve, and also for injecting gas into the combustion chamber. A direct injection type fuel injection device including one gas injection valve, including one fuel injection valve, and corresponding to the fuel injection valve, provided with one or more fuel injection holes opened in the combustion chamber. And at least one gas injection valve, corresponding to the gas injection valve, provided with one or more gas injection holes opened in the combustion chamber, and the shape, size, direction and Specifying the arrangement, specifying the number, shape, size, orientation, and arrangement of the fuel injection holes with respect to the fuel injection holes, and the pressure of the fuel injected from the fuel injection valve is in the range of 1 to 4 MPa. Set to a predetermined value, from the fuel injection valve And fuel injected Isa is in the combustion chamber through the fuel injection hole, and the spirit that is configured as is injected from a gas injection valve colliding with the gas to be injected into the combustion chamber through the gas injection holes.

  According to the structure of the said invention, unlike the invention of Claim 1, especially the pressure of the fuel injected from a fuel injection valve is set to the predetermined value of the range of 1-4 MPa. Here, the particle size of the fuel spray has a relationship close to −½ power with respect to the fuel pressure. Further, by lowering the fuel pressure, the energy of the gas jet becomes relatively large with respect to the fuel spray. Therefore, by reducing the fuel pressure in a region where the particle size of the fuel spray does not change so much, the rate at which the spray length changes is relatively large.

  In order to achieve the above object, according to a fourth aspect of the present invention, in the first or third aspect of the present invention, the collision angle between the fuel injected from the fuel injection hole and the gas injected from the gas injection hole is It is intended to be set to a predetermined value in the range of 15 to 75 °.

  According to the configuration of the invention, in addition to the operation of the invention according to claim 1 or 3, the collision angle between the fuel injected from the fuel injection hole and the gas injected from the gas injection hole is in a range of 15 to 75 °. Therefore, the acting force of the gas jet in the direction of fuel spray becomes large, and the spray length can be extended.

  In order to achieve the above object, according to a fifth aspect of the invention, in the first aspect of the invention, the pressure of the fuel injected from the fuel injection valve is set to a predetermined value in the range of 1 to 4 MPa. Intended to be

  According to the configuration of the invention, in addition to the operation of the invention of claim 1, the pressure of the fuel injected from the fuel injection valve is set to a predetermined value in the range of 1 to 4 MPa. The energy of the gas jet becomes relatively large with respect to the fuel spray. Therefore, the fuel pressure decreases in a region where the particle size of the fuel spray does not change so much, and the rate at which the spray length changes relatively increases.

  In order to achieve the above object, according to a sixth aspect of the present invention, in the first aspect of the invention, the collision angle between the fuel injected from the fuel injection hole and the gas injected from the gas injection hole is 15 to 15. It is intended that the predetermined value in the range of 75 ° and the pressure of the fuel injected from the fuel injection valve are set to a predetermined value in the range of 1 to 4 MPa.

  According to the configuration of the invention described above, in addition to the operation of the invention according to claim 1, the collision angle between the fuel injected from the fuel injection hole and the gas injected from the gas injection hole is in a range of 15 to 75 °. Since it is set to a value, the acting force of the gas jet in the direction of fuel spray becomes large, and the spray length can be extended. Moreover, since the pressure of the fuel injected from the fuel injection valve is set to a predetermined value in the range of 1 to 4 MPa, the fuel pressure is relatively lowered, and the energy of the gas jet is relatively increased with respect to the fuel spray. . Therefore, the fuel pressure decreases in a region where the particle size of the fuel spray does not change so much, and the rate at which the spray length changes is assumed to be large.

  According to the first aspect of the present invention, suitable fuel atomization can be achieved over the entire operating condition of the internal combustion engine, and the spray length can be set to be relatively long.

  According to the second aspect of the present invention, suitable fuel atomization can be achieved over the entire operating condition of the internal combustion engine, and the spray length can be set relatively long.

  According to the third aspect of the present invention, suitable fuel atomization can be achieved over the entire operating condition of the internal combustion engine, and the change ratio of the spray length can be set relatively large. .

  According to invention of Claim 4, in addition to the effect of the invention of Claim 1 or 3, spray length can be made longer.

  According to the invention described in claim 5, in addition to the effect of the invention described in claim 1, the change rate of the spray length can be relatively increased.

  According to the invention described in claim 6, in addition to the effect of the invention described in claim 1, the spray length can be made longer, and the change ratio of the spray length can be relatively increased.

[First Embodiment]
Hereinafter, a first embodiment of a direct injection fuel injection device according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration diagram of a direct injection engine system including a direct injection fuel injection device of the present invention. A direct injection engine system mounted on an automobile includes a reciprocating type multi-cylinder engine 1 having a known structure. Each combustion chamber 2 formed in each cylinder of the engine 1 is provided with a direct injection type fuel injection device (hereinafter simply referred to as “fuel injection device”) 3. The fuel injection device 3 is configured to inject fuel and air directly into the combustion chamber 2. The engine 1 explodes and burns a combustible mixture of air sucked through the intake passage 4, fuel injected from the fuel injection device 3, and air in the combustion chamber 2 of each cylinder, and exhausts the exhaust gas after the combustion. By discharging to the outside through the passage 5, the piston 6 is operated to rotate the crankshaft 7 to obtain power.

  A throttle valve 8 provided in the intake passage 4 is opened and closed to adjust the amount of air (intake amount) Ga taken into the combustion chamber 2 of each cylinder through the passage 4. The valve 8 operates in conjunction with an operation of an accelerator pedal (not shown) provided in the driver's seat. A throttle sensor 21 provided corresponding to the throttle valve 8 detects an opening degree (throttle opening degree) TA of the valve 8 and outputs an electric signal corresponding to the detected value. Since the throttle valve 8 is interlocked with the operation of the accelerator pedal, the operation of the accelerator pedal is reflected in the throttle opening degree TA detected by the throttle sensor 21. An intake pressure sensor 22 provided in the surge tank 9 of the intake passage 4 detects the pressure (intake pressure) PM of intake air in the intake passage 4 downstream of the throttle valve 8 and outputs an electric signal corresponding to the detected value. To do.

  Each fuel injection device 3 directly injects fuel and air into the corresponding combustion chamber 2. Each fuel injection device 3 is supplied with fuel and air at a predetermined pressure by a predetermined fuel supply device and an air supply device (both not shown). The fuel and air supplied to each fuel injection device 3 are injected into the corresponding combustion chamber 2 by the operation of the device 3. Air is taken into the intake passage 4 from the outside through the air cleaner 10. The air taken into the intake passage 4 is taken into the combustion chamber 2 of each cylinder. Fuel and air are injected from each fuel injection device 3 into the air to form a combustible air-fuel mixture.

  The ignition plugs 11 provided in the combustion chambers 2 of the respective cylinders perform an ignition operation in response to an ignition signal output from the ignition coil 12. Each spark plug 11 and ignition coil 12 constitute an ignition device for igniting a combustible mixture formed in the combustion chamber 2.

  The catalytic converter 13 provided in the exhaust passage 5 incorporates a three-way catalyst for purifying exhaust exhausted from the combustion chamber 2. In the exhaust passage 5, an oxygen sensor 23 provided on the upstream side of the catalytic converter 13 detects the oxygen concentration Ox in the exhaust discharged from the combustion chamber 2 to the exhaust passage 5, and outputs an electric signal corresponding to the detected value. Output.

  The water temperature sensor 24 provided in the engine 1 detects the temperature (cooling water temperature) THW of the cooling water flowing inside the engine 1 and outputs an electrical signal corresponding to the detected value. A rotation speed sensor 25 provided in the engine 1 detects the rotation speed of the crankshaft 7 as the engine rotation speed NE and outputs an electrical signal corresponding to the detected value. The sensor 25 detects a change in the rotation angle (crank angle) of the crankshaft 7 for each predetermined angle and outputs the detection as a pulse signal. An ignition switch 26 provided in the driver's seat outputs a start signal when turned on to start the engine 1. The ignition switch 26 outputs a stop signal when it is turned off to stop the engine 1.

  In this embodiment, the throttle sensor 21, the intake pressure sensor 22, the oxygen sensor 23, the water temperature sensor 24, the rotation speed sensor 25, and the like described above are used as the operation state detection means of the present invention for detecting the operation state of the engine 1. Equivalent to. In this embodiment, the intake air amount Ga is converted from the values of the intake pressure PM and the engine rotational speed NE detected by the intake pressure sensor 22 and the rotational speed sensor 25.

  In this embodiment, an electronic control unit (ECU) 30 inputs various signals output from a throttle sensor 21, an intake pressure sensor 22, an oxygen sensor 23, a water temperature sensor 24, a rotation speed sensor 25, and an ignition switch 26. The ECU 30 executes fuel injection control, ignition timing control, and the like based on these input signals, and controls each fuel injection device 3 and the ignition coil 12 respectively.

  Here, the fuel injection control is to control the fuel injection amount, the fuel injection timing, and the fuel spray by controlling each fuel injection device 3 in accordance with the operating state of the engine 1. The ignition timing control is to control the ignition timing by each spark plug 11 by controlling the ignition coil 12 in accordance with the operating state of the engine 1.

  As is well known, the ECU 30 includes a central processing unit (CPU) 31, a read only memory (ROM) 32, a random access memory (RAM) 33, a backup RAM (BU RAM) 34, and the like. The ROM 32 stores in advance a predetermined control program related to the various controls described above. The ECU 30 (CPU 31) executes the various controls described above in accordance with these control programs.

  FIG. 2 is a cross-sectional view showing how the fuel injection device 3 is attached to the engine 1. This fuel injection device 3 includes a fuel injection valve 43 for injecting fuel into the combustion chamber 2 of the engine 1 and an air injection as a gas injection valve for injecting air (air) as gas into the combustion chamber 2. And a valve 44. The engine 1 includes a cylinder block 45 and a cylinder head 46. The piston 6 is provided in the cylinder bore 47 provided in the cylinder block 45 so that reciprocation is possible. The combustion chamber 2 is configured as a space surrounded by the cylinder bore 47, the piston 6, and the cylinder head 46. As shown in FIG. 1, the cylinder head 46 is provided with an intake port 4 a and an exhaust port 5 a that communicate with each combustion chamber 2. Each intake port 4 a is provided with a known intake valve 14. A known exhaust valve 15 is provided in the exhaust port 5a. The fuel injection valve 43 and the air injection valve 44 are integrally attached to the cylinder head 46 by an attachment member 49 corresponding to the combustion chamber 2. The fuel injection valve 43 and the air injection valve 44 are assembled to the mounting member 49 so that both central axes L1 and L2 cross each other obliquely.

  A fuel injection valve 43 constituted by a known solenoid valve includes a housing 51, a core 52 assembled to the housing 51, an adjustment pipe 53 provided inside the core 52, and between the housing 51 and the core 52. A solenoid 54 provided, a lower body 55 provided on the front end side of the housing 51, a nozzle body 56 provided in the lower body 55, and a valve body member 57 provided between the nozzle body 56 and the core 52. With. The valve body member 57 includes a valve shaft 58 having a valve portion 58 a at the distal end, and an armature 59 assembled to the proximal end of the valve shaft 58. A compression spring 60 is provided between the armature 59 and the adjustment pipe 53. The base end portion of the core 52 is a pipe connector 61 connected to a fuel pipe (not shown). An O-ring 62 is provided on the outer periphery of the pipe connector 61. Inside the pipe connector 61, a strainer 63 for removing foreign matter is provided. The housing 51 is provided with a wiring connector 64 connected to the electrical wiring. Here, since the basic configurations of the fuel injection valve 43 and the air injection valve 44 are substantially the same, the configuration of the air injection valve 44 is denoted by the same reference numerals as those of the components of the fuel injection valve 43, and description thereof is omitted. .

  In FIG. 3, the conceptual diagram regarding the electrical wiring which concerns on the fuel injection valve 43 and the air injection valve 44, fuel piping, and air piping is shown. As shown in FIG. 3, a fuel pipe 71 is connected to the pipe connector 61 of the fuel injection valve 43. An air pipe 72 is connected to the pipe connector 61 of the air injection valve 44. The fuel pipe 71 is provided with a pressure regulator 73 and a fuel pump 74. The air pipe 72 is provided with a pressure regulator 75 and an air pump 76. Each pump 74, 76 is driven by a corresponding motor 77, 78, respectively. When the fuel pump 74 is driven, fuel in a fuel tank (not shown) is discharged from the pump 74 and supplied to the fuel injection valve 43 as a constant high-pressure fuel via the pressure regulator 73. When the air pump 76 is driven, air is discharged from the pump 76 and supplied to the air injection valve 44 as pressurized air via the pressure regulator 75.

  As shown in FIG. 3, the wiring connector 64 of the fuel injection valve 43 and the wiring connector 64 of the air injection valve 44 are electrically connected to the ECU 30, respectively. The fuel injection valve 43 and the air injection valve 44 each operate based on an injection signal sent from the ECU 30. By operating the fuel injection valve 43 based on the injection signal from the ECU 30, high-pressure fuel is injected from the injection valve 43. Further, the air injection valve 34 operates based on the injection signal from the ECU 30, whereby pressurized air is injected from the injection valve 44. In this embodiment, the ECU 30 corresponds to the control means of the present invention for independently controlling the fuel injection valve 43 and the air injection valve 44.

  FIG. 4 shows an enlarged cross-sectional view of the distal end portion of the attachment member 49. As shown in FIGS. 2 to 4, the mounting member 49 having a block shape includes a cylindrical portion 49 a directed to the combustion chamber 2, a first assembly hole 49 b in which the lower body 55 of the fuel injection valve 43 is assembled, an air injection valve And a second assembly hole 49c into which 44 nozzle bodies 56 are assembled. The cylindrical portion 49a and the first assembly hole 49b are arranged on the same axis and are partitioned by a partition wall 49d. A hole 49e is formed in the center of the partition wall 49d. A tube 66 having a hole 66a is provided at the center of the cylindrical portion 49a. A valve seat 56a corresponding to the valve portion 58a is formed in the nozzle body 56 assembled in the first assembly hole 49b. The valve hole 56b of the valve seat 56a is aligned with the two holes 49e and 66a to form a single fuel passage 67. The attachment member 49 is formed with a hole 49f extending from the center of the second assembly hole 49c toward the inside of the cylindrical portion 49a. The hole 49f is disposed so as to cross obliquely with respect to the center of the cylindrical portion 49a. A valve seat 56a corresponding to the valve portion 58a is formed in the nozzle body 56 assembled in the second assembly hole 49c. The valve hole 56b of the valve seat 56a is aligned with the oblique hole 49f to form a single air passage 68. An orifice plate 69 is fixed to the open end of the cylindrical portion 49a. At the center of the orifice plate 69, one fuel injection hole 69 a is provided corresponding to the fuel injection valve 43. The fuel injection hole 69 a is opened to the combustion chamber 2 and aligned with the fuel passage 67. The orifice plate 69 is provided with a plurality of air injection holes 69 b corresponding to the air injection valves 44 as gas injection holes. These air injection holes 69b are disposed in the vicinity of the fuel injection holes 69a, open to the combustion chamber 2, and communicate with the inside of the cylindrical portion 49a. Accordingly, the high-pressure fuel injected from the fuel injection valve 43 passes through the fuel passage 67 and is injected from the fuel injection holes 69 a of the orifice plate 69 into the combustion chamber 2. Further, the pressurized air injected from the air injection valve 44 is once injected into the cylindrical portion 69 a through the fuel passage 68 and further injected into the combustion chamber 2 from each air injection hole 69 b of the orifice plate 69.

  Here, the above “near” means that the atomization effect of the fuel spray and the variable effect of the fuel spray length can be obtained even when the following injection conditions are changed. It means the distance to the center. Specifically, as an example, as shown in FIG. 8, when the distance from the center of the fuel injection hole to the center of the air injection hole is “X”, the following conditions (Equation 1) to (Equation 3) are satisfied. “X” that satisfies the condition can be defined as the “neighborhood”.

From the general theory of motion related to gas injection, the reach distance “L (m)” and the jet angle “α (°)” of the gas jet are expressed as follows.
L = (ρa / ρo) ^0.25 * (d * u * t / tan α) ^0.5 (Expression 1)
tan α = 0.427 * (ρo / ρa) ^0.35 (Formula 2)
Here, "ρa" is gas density at the absolute pressure of the injection gas (kg / m ^3), the gas density (kg / m ³⁾ of the "ρo" within the cylinder (injection field), "d" is the gas injection hole (Or shortest width (m)), “u” is the initial gas injection speed (m / s), “t” is the time after injection (s), and “α” is the temporary jet half-angle value (°). is there.

When the jet velocity at the collision point is calculated from the above equation, and a limiting condition for changing the fuel spray atomization and spray length obtained from predetermined experimental values and calculated values is added, the distance "X"
X ≦ a * d * Pa ^0.5 * ρa ^0.35 * ρo ^−0.85 (Formula 3)
It is expressed. Here, “X” is the maximum distance (m) in the vicinity, and “Pa” is the absolute pressure (Pa) of the injected gas. “0.03” can be applied to “a”.

As an example, assuming that the injection gas is air, the air injection diameter, the injection pressure, the gas density at the absolute pressure of the injection gas, and the gas density in the cylinder (injection field) are d ≦ 0.0005 (m), Pa ≦ 600,000 (Pa) , Ρa ≦ 7.23 (kg / m ³ ) and ρo ≧ 1.205 (kg / m ³ ), X ≦ 0.0199 (m) = 19.9 (mm). Therefore, unless the gas nozzle hole is disposed within “19.9 mm” from the fuel nozzle hole, the atomization effect of the fuel spray and the spray length variable effect cannot be obtained under this injection condition.

  FIG. 5 shows a plan view of the orifice plate 69. FIG. 6 is a cross-sectional view taken along line AA in FIG. As shown in FIGS. 5 and 6, the fuel injection hole 69 a has a circular cross section and penetrates perpendicularly to the end face of the orifice plate 69. The plurality of air injection holes 69b are similarly circular in cross section (open ends are oval) and penetrate obliquely with respect to the end face of the orifice plate 69. As shown in FIG. 5, a plurality (eight in this case) of air injection holes 69b are arranged at equiangular intervals on a circumference centered on the fuel injection holes 69a. In this embodiment, the inner diameter of the fuel injection hole 69a is set to “0.6 mm”, and the inner diameter of each air injection hole 69b is set to “1.0 mm”.

  As shown in FIG. 6, the center line of the fuel injection hole 69a and the center line of each air injection hole 69b are set to intersect each other at one point (hereinafter referred to as “collision point”) HP. That is, fuel spray is formed by injecting fuel from the fuel injection hole 69a toward the collision point HP. Moreover, an air jet is formed by injecting air from each air injection hole 69b toward this collision point HP. Therefore, the fuel spray and each air jet collide with each other around the collision point HP. As described above, in this embodiment, the directions of the air injection holes 69b and the fuel injection holes 69a are such that the air jets injected from the air injection holes 69b collide with the fuel spray injected from the fuel injection holes 69a. Are set respectively.

  7A to 7C are conceptual diagrams of fuel spray and air jet. As shown in FIG. 7A, the fuel spray has a substantially conical shape that is substantially the same on the front and side surfaces. The spray spread angle (spray angle) θ1 is determined by the size of the inner diameter of the fuel injection hole 69a in the orifice plate 69. As shown in FIG. 7B, one air jet (free jet) has a conical shape that is substantially the same on the front and side surfaces. The spread angle (jet angle) θ2 of the jet is determined by the size of the inner diameter of the air nozzle hole 69b in the orifice plate 69 and the like. As shown in FIG.7 (c), the air jet (perforated jet) from the circumference injected from the several air nozzle hole 69b makes the crown shape which is substantially the same on the front and the side. Here, generally, the energy of the gas jet decreases as the distance from the gas nozzle hole increases. Therefore, the collision point HP in the fuel spray is maintained at a distance from the air injection hole 69b so that the energy of the air jet interferes with the fuel spray and the atomization of the fuel spray and the spray length and spray shape can be adjusted. Set to position. Further, the size (outer diameter (width)) of the air jet injected from each air injection hole 69b at the collision point HP is approximately the same as the outer diameter D1 at the collision point HP of the fuel spray injected from the fuel injection hole 69a. Is set to be Here, the “size of the air jet” that is approximately the same as the outer diameter D1 of the fuel spray is the “jet angle β” and “outer diameter b” of the air jet shown in FIG. 9 and the air shown in FIG. It is defined by “distance c” from the nozzle hole to the collision point HP and a predetermined expression “b = 2 * c * tan (β / 2)”. As described above, the fuel injection device 3 is configured to cause the fuel injected from the fuel injection valve 43 and the air injected from the air injection valve 44 to collide in the combustion chamber 2.

  FIGS. 10A to 10C are conceptual diagrams showing the difference between the fuel spray strength (spray strength) and the air jet strength (jet strength) at the collision point HP. As shown to Fig.10 (a), a fuel spray shows the spray intensity | strength which has the same distribution width on the front and the side. As shown in FIG. 10B, one air jet (free jet) exhibits jet strength having the same distribution width on both the front and side surfaces. This jet strength is slightly lower than the spray strength. As shown in FIG.10 (c), the jet strength by several air jets (perforated jet) has the same distribution width on the front surface and the side surface. The jet strength of this porous jet is higher than the jet strength of the one air jet. In this way, the intensity distribution of the air jet is set to overlap evenly with the intensity distribution of the fuel spray. Here, the spray strength and jet strength can be calculated by the product of the flow velocity and the density.

  According to the fuel injection device 3 of this embodiment configured as described above, the fuel injected from one fuel injection valve 43 is injected into the combustion chamber 2 from the corresponding one fuel injection hole 69a. A fuel spray is formed in the combustion chamber 2. The form of this fuel spray is determined by specifying the shape, size, and direction of the fuel injection hole 69a. On the other hand, air injected from one air injection valve 44 is injected into the combustion chamber 2 from the corresponding plurality of air injection holes 69 b, thereby forming an air jet in the combustion chamber 2. The influence on the form of the air jet and the fuel spray is determined by specifying the number, shape, size, direction, and arrangement of the air nozzles 69b with respect to the fuel nozzles.

  Here, the air jet axis AL (see FIG. 4) extending from each air nozzle hole 69b is set to intersect at the center of the maximum diameter D1 (see FIG. 7A) in the fuel spray from the fuel nozzle hole 69a. Is done. Therefore, according to the form of fuel spray, each air jet collides with respect to the whole around the collision point HP, and the intensity distribution of the air jet with respect to the fuel spray becomes equivalent. As a result, the fuel spray can be equivalently finer and finer in the entire spray, and fuel atomization can be promoted. Thereby, the combustion performance of the direct injection type engine 1 can be improved.

  In particular, in this embodiment, since the fuel injection hole 69a of the orifice plate 69 is circular, the fuel spray has a conical shape, and the spray angle θ1 of the fuel spray (see FIG. 7A) is the fuel injection hole. It is determined by the size of the inner diameter of 69a. Further, since each air nozzle hole 69b of the orifice plate 69 is circular, each air jet has a conical shape, and the jet angle θ2 (see FIG. 7B) of these air jets is the inner diameter of each air nozzle 69b. It is determined by the size of. Here, a plurality of air injection holes 69b are arranged at equiangular intervals on the circumference centered on the fuel injection hole 69a, and a plurality of air jets from each air injection hole 69b as shown in FIG. 7C. Is tilted toward one collision point HP. Therefore, a plurality of air jets collide with the conical fuel spray and the intensity distribution of the air jets with respect to the fuel spray becomes equal. As a result, the air spray can be collided equally over the entire width direction of the spray according to the shape of the fuel spray. Fine fuel atomization can be achieved, and fuel atomization can be promoted.

  In this embodiment, each air injection hole 69b is disposed in the vicinity of the fuel injection hole 69a. Here, in order to set the spray length and the spray shape of the fuel spray by the air jet, the energy of the air jet interferes with the fuel spray at the collision point HP between the fuel spray and the air jet, and the fuel atomization and the spray length. And it is necessary to keep it to the extent that the spray shape can be set. The energy of this air jet becomes smaller as the distance from each air nozzle 69b increases. Therefore, the collision point HP between the air jet and the fuel spray is set near the fuel injection hole 69a by arranging each air injection hole 69b in the vicinity of the fuel injection hole 69a. Thereby, fuel atomization, spray length, and spray shape can be set suitably.

  In this embodiment, the size of the air jet injected from each air injection hole 69b is set to be approximately the same as the size of the fuel spray injected from the fuel injection hole 69a. Therefore, the air jet collides with the fuel spray mode, and the fuel atomization and the spray length and spray shape can be suitably set throughout the fuel spray. For this reason, by making an air jet of the same size collide with the fuel spray, finer fuel atomization can be achieved throughout the fuel spray.

  In this embodiment, since both the fuel injection hole 69a and each air injection hole 69b have a circular cross section, the processing of the injection holes 69a and 69b can be performed relatively easily by drilling using a punch or the like. . For this reason, the orifice plate 69 can be manufactured relatively easily. Further, by simply changing the pressure and the shape (for example, “taper”) of each air nozzle hole 69b, the air jet spread angle (jet angle) θ2 (see FIG. 7B) is changed, and the air jet strength distribution is changed. Adjusted. Furthermore, simply by changing the inner diameter of the circular fuel injection hole 69a, the spread angle (spray angle) θ1 (see FIG. 7A) of the fuel spray is changed, and the fuel spray intensity distribution is adjusted. Thereby, the particle size level to be atomized can be arbitrarily set arbitrarily. At the same time, by adjusting the spray angle θ1 and the jet angle θ2, and adjusting the directions of the fuel spray and the air spray, the spray length and the spray shape can be arbitrarily set arbitrarily.

  FIG. 11 shows a conceptual diagram when a plurality of air jets collide with fuel spray. In this embodiment, as shown in FIGS. 7A to 7C, a plurality of air jets having the same size and intensity distribution are caused to collide with one fuel spray at one collision point HP. Even if the intensity distribution is non-uniform, the air jet can uniformly affect the entire spray. Thereby, it turns out that fuel can be atomized suitably and spray length etc. can be set up suitably.

  In this embodiment, the fuel injection valve 43 and the air injection valve 44 are integrally attached to the cylinder head 46 by the attachment member 49 corresponding to the combustion chamber 2. Therefore, compared with the case where each injection valve 43 and 44 is attached separately, the positional accuracy of the air injection hole 69b with respect to the fuel injection hole 69a becomes high, and the process and work of the cylinder head 46 for attachment are reduced. Further, if the fuel injection valve 43 and the air injection valve 44 are assembled in advance to the mounting member 49 and assembled, the injection valves 43 and 44 can be mounted on the cylinder head 46 at the same time by simply mounting the mounting member 49 on the cylinder head 46. It is done. For this reason, manufacture of a fuel-injection apparatus can be simplified.

  Next, the fuel injection control process executed by the ECU 30 in order to make the fuel spray length, spray particle size, and spray shape variable will be described. FIG. 12 is a flowchart showing the “fuel injection control routine”. The ECU 30 periodically executes this routine every predetermined time while the engine 1 is operating.

  First, in step 201, the ECU 30 reads detection signals from the throttle sensor 21, the intake pressure sensor 22, the oxygen sensor 23, the water temperature sensor 24, and the rotation speed sensor 25, respectively.

  In step 202, the ECU 30 determines the operating state of the engine 1 based on the read detection signal. In this embodiment, the ECU 30 determines an operation state including “low temperature start operation”, “partial load operation”, and “full load operation”. For example, when the coolant temperature THW is relatively low, the engine speed NE is relatively low, and the throttle opening degree TA is relatively small, the ECU 30 determines that “low temperature start operation”. In addition, when the coolant temperature THW is high to some extent, the engine speed NE is high to some extent, and the throttle opening degree TA is slightly changed, the ECU 30 determines “partial load operation”. Further, when the coolant temperature THW is high to some extent, the engine speed NE is high to some extent, and the throttle opening degree TA changes to full open, the ECU 30 determines “full load operation”.

  In step 203, the ECU 30 determines an optimal combustion pattern according to the determined operating state. In this embodiment, combustion patterns suitable for various operating conditions are experimentally confirmed and set in advance. FIG. 13 is a table showing the relationship between the operating state and the combustion pattern. As can be seen from this table, in the case of “low temperature start operation”, “warm-up combustion” is determined as the combustion pattern. In the case of “partial load operation”, “stratified combustion” is determined as the combustion pattern. In the case of “full load operation”, “uniform combustion” is determined as the combustion pattern.

  In step 204, the ECU 30 determines the “fuel injection period”, “air injection period”, and “fuel / air injection timing difference” by the fuel injection valve 43 and the air injection valve 44, respectively, according to the determined combustion pattern. decide. For example, in the case of “warm-up combustion”, as shown in FIG. 13, the “fuel / air injection period” is determined to be “synchronous”, and the fuel / air injection timing difference is determined to be “same timing”. In the case of “stratified combustion”, the “fuel / air injection period” is determined to be “longer air injection period” as shown in FIG. It is determined to be “preceding”. Further, in the case of “uniform combustion”, as shown in FIG. 13, the “fuel / air injection period” is determined to be “slightly longer air injection period”, and the fuel / air injection timing difference is “air injection timing”. Is slightly ahead ".

  In step 205, the ECU 30 determines the opening / closing timing of the fuel injection valve 43 and the air injection valve 44 corresponding to the change in the crank angle from the determined “fuel / air injection period” and “fuel / air injection timing difference”. Set each. For example, in the case of “warm-up combustion”, as shown in FIGS. 14A and 14B, the opening timing of the fuel injection valve 43 and the air injection valve 44 is similarly in the range from the angle a0 to the angle a3. Set to. In the case of “stratified combustion”, as shown in FIGS. 15A and 15B, the opening timing of the fuel injection valve 43 is set in a range from the angle a2 to the angle a3, and the air injection valve The opening timing of 44 is set in a range from an angle a0 preceded by an angle difference ΔA from an angle a2 of the fuel injection valve 43 to an angle a3 like the fuel injection valve 43. Further, in the case of “uniform combustion”, as shown in FIGS. 16A and 16B, the opening timing of the fuel injection valve 43 is set in a range from the angle a2 to the angle a3, and the air injection valve 44 is set to a range from an angle a1 slightly ahead of the angle a2 of the fuel injection valve 43 by an angle difference ΔB (ΔB <ΔA) to an angle a3 similar to the fuel injection valve 43.

  In step 206, the ECU 30 outputs a fuel injection signal and an air injection signal corresponding to the set opening / closing timing to the fuel injection valve 43 and the air injection valve 44, respectively.

  The reason for controlling the opening / closing timing of the fuel injection valve 43 and the air injection valve 44 as described above is to control the fuel spray length, the spray particle size, and the spray shape of the fuel injection device 3. That is, the ECU 30 sets the fuel injection timing and the fuel injection period by the fuel injection valve 43 to be constant corresponding to the change in the crank angle in order to control the fuel spray length, the spray particle size, and the spray shape. Both the air injection timing and the air injection period by the air injection valve 44 are controlled based on the operation state determined for the engine 1. More specifically, the ECU 30 makes the air injection timing by the air injection valve 44 the same as the fuel injection timing by the fuel injection valve 43 and achieves the air injection by the air injection valve 44 in order to achieve “warm-up combustion”. The period is made equal to the fuel injection period by the fuel injection valve 43. Further, the ECU 30 causes the air injection timing by the air injection valve 44 to precede or slightly precede the fuel injection timing by the fuel injection valve 43 in order to achieve “stratified combustion” and “uniform combustion”. The air injection period is made longer than the fuel injection period by the fuel injection valve 43 by the angle difference ΔA or the angle difference ΔB depending on the crank angle.

  According to the fuel injection control, as shown in FIG. 13, in “warm-up combustion”, the fuel / air injection period is set to “synchronous” and the injection timing difference is set to “same timing”. Thereby, the spray characteristic that the spray length is relatively short, the spray particle size is relatively small, and the spray shape is large in spray angle is obtained. FIG. 17 shows an image of the spray characteristics. During the cold start operation of the engine 1, the spray length is relatively short to prevent the fuel from adhering to the top surface of the piston 6, the spray particle size is relatively small to promote fuel evaporation, and the fuel is supplied to the combustion chamber 2. It is desirable to make the spray shape a large spray angle in order to disperse the whole of the spray. Therefore, the spray characteristics for the “warm-up combustion” are suitable for the low temperature start operation of the engine 1.

  On the other hand, as shown in FIG. 13, in “stratified combustion”, the fuel / air injection period is set to “long air injection period” and the injection timing difference is set to “air injection timing preceded”. Is relatively long, the spray particle size is relatively small, and the spray characteristics in which the spray shape is a small spray angle are obtained. FIG. 18 shows an image diagram of the spray characteristics. During partial load dynamic operation of the engine 1, a strong (penetration distance) is provided so that a stable air-fuel mixture can be collected around the spark plug without being affected by disturbance such as airflow fluctuation in the combustion chamber 2. Long spraying is required. In addition, since it receives heat from the piston 6, high atomization as in the low temperature start operation is not required, but in order to be able to form a stable air-fuel mixture, a smaller spray particle size is desired. Furthermore, a spray shape having a small spray angle suitable for spray stratification is required. Therefore, the spray characteristics for the above “stratified combustion” are suitable when the engine 1 is partially loaded.

  On the other hand, as shown in FIG. 13, in “uniform combustion”, the fuel / air injection period is set to “slightly longer air injection period” and the injection timing difference is set to “slightly ahead of air injection timing”. Thereby, the spray characteristic in which the spray length is relatively medium, the spray particle size is relatively small, and the spray shape is in the spray angle is obtained. FIG. 19 shows an image diagram of the spray characteristics. At the time of full load dynamic operation of the engine 1, the heat received from the wall surface of the combustion chamber 2 can be expected although the conditions are the same as those at the low temperature start operation. Therefore, it is required to make the spray length longer than that at the low temperature start operation and shorter than that at the partial load operation. Further, in order to form a stable air-fuel mixture, it is required to make the spray particle size smaller than the current state. Furthermore, it is required that the spray angle be smaller than that at the low temperature start operation and larger than that at the partial load operation. Accordingly, the spray characteristics for “uniform combustion” are suitable for full load operation of the engine 1.

  According to the fuel injection control device of this embodiment described above, fuel spray is formed in the combustion chamber 2 by injecting fuel from the fuel injection holes 69 a into the combustion chamber 2 in the fuel injection device 3. On the other hand, air is injected into the combustion chamber 2 from each air injection hole 69 b in the fuel injection device 3, thereby forming an air jet in the combustion chamber 2. In this configuration, the directions of the air injection holes 69b and the fuel injection holes 69a are set so that the air jets injected from the air injection holes 69b collide with the fuel spray injected from the fuel injection holes 69a. When the air jet collides with the fuel spray, the form of the fuel spray is changed.

  Here, in order to control the spray length, the spray particle size, and the spray shape (spray angle) of the fuel spray injected from the fuel injection hole 69a, the ECU 30 controls the fuel injection valve 43 and the air based on the operating state of the engine 1. The injection valves 44 are controlled independently. In this control, the ECU 30 particularly controls both the air injection timing and the air injection period by the air injection valve 44. Thereby, in the direct injection type engine 1, the fuel spray length, the spray particle size, and the spray shape (spray angle) can be changed according to the difference in the operation state, and the fuel has the optimum characteristics for the operation state. A spray can be obtained. As a result, the fuel combustion performance in the combustion chamber 2 of the engine 1 can be improved. Thereby, the exhaust emission of the engine 1 can be improved, and the fuel consumption and output of the engine 1 can be improved.

  Here, the mechanism regarding control of spray length is demonstrated. As shown in FIG. 14, the spray length becomes relatively short by controlling the opening and closing timings of the fuel injection valve 43 and the air injection valve 44 so that the air injection timing is the same as the fuel injection timing and the air injection period. Is the same as the fuel injection period. This is because the air jet formed simultaneously with the fuel spray becomes a resistance of the fuel spray. On the other hand, the spray length becomes relatively long as shown in FIGS. 15 and 16 by controlling the opening / closing timing of the fuel injection valve 43 and the air injection valve 44 so that the air injection timing precedes the fuel injection timing. Or when it is slightly advanced. This is because the air jet formed prior to or slightly ahead of the fuel spray gives momentum to the fuel spray. Therefore, the spray length can be made variable by changing the leading degree of the air injection timing with respect to the fuel injection timing.

  20A to 20C show control examples related to the spray length. 20A to 20C show the state of fuel spray formed using the fuel injection device 3. FIG. 20A shows fuel spray when air injection is not performed during fuel injection. FIG. 20B shows fuel spray when air injection is preceded by “1.0 ms” with respect to fuel injection. FIG. 20C shows fuel spray when air injection is preceded by “2.0 ms” with respect to fuel injection. As is apparent from FIGS. 20A to 20C, it is understood that the spray length becomes relatively longer as the advance of the air injection to the fuel injection is advanced.

  Next, a mechanism related to control of the spray particle size will be described. As shown in FIGS. 14 to 16, the spray particle size becomes relatively small by controlling the opening and closing timings of the fuel injection valve 43 and the air injection valve 44, and thereby the relationship between the air injection timing and the fuel injection timing, This is all the cases when the relationship between the air injection period and the fuel injection period is changed. In any case, this is because the fuel spray particles are divided by the collision of the air jet with the fuel spray.

  Next, a mechanism related to control of the spray shape will be described. The spray shape (spray angle) changes as shown in FIGS. 14 to 16 by controlling the opening and closing timings of the fuel injection valve 43 and the air injection valve 44, and the relationship between the air injection timing and the fuel injection timing. This is all cases when the relationship between the injection period and the fuel injection period is changed. As shown in FIG. 13, the “spray angle is large” due to the control for “warm-up combustion” because the fuel / air injection period and the fuel / air injection timing are the same. This is because the dispersion to the surroundings when the two collide is improved. As shown in FIG. 13, the “spray angle is small” by the control for “stratified combustion” is that the fuel spray rides on the air flow and extends in the injection direction by increasing the spray length by preceding the air injection. At the same time, in the width direction, even if there is an air collision, the spread becomes smaller as the length increases. As shown in FIG. 13, the reason for “in spray angle” by the control for “uniform combustion” is that the leading degree of air injection is smaller than that of “stratified combustion”.

  In the fuel injection control for “warm-up combustion”, “stratified combustion”, and “uniform combustion”, the change of the fuel / air injection timing and the change of the fuel / air injection period are combined with each other. As described above, when the fuel / air injection timing and the fuel / air injection period are individually changed, it is considered that the following effects are obtained.

  When the ECU 30 causes the air injection timing by the air injection valve 44 to precede the fuel injection timing by the fuel injection valve 43, the fuel spray length is relatively long and the fuel spray particle size is relatively small. Thus, a fuel spray having characteristics suitable for stratified combustion can be obtained. Thereby, the combustion performance of the fuel in the engine 1 can be improved.

  Further, when the ECU 30 makes the air injection period of the air injection valve 44 equal to the fuel injection period of the fuel injection valve 43, the fuel spray particle size becomes relatively small throughout the fuel injection period. Thereby, the combustion performance of the fuel in the engine 1 can be improved.

  Further, when the ECU 30 makes the air injection period by the air injection valve 44 longer than the fuel injection period by the fuel injection valve 43, the fuel spray length becomes relatively long, and the spray particle size is increased over the entire area of the fuel spray. Relatively small. Thereby, the combustion performance of the fuel in the engine 1 can be improved.

  In this embodiment, a specific effect can be acquired by embodying each component in the following Examples 1-3.

<Example 1>
As shown in FIG. 21, by setting the collision angle θ3 between the fuel spray injected from the fuel injection hole 69a and the air jet injected from the air injection hole 69b, the spray length of the fuel spray is relatively shortened, It can be relatively long.

  When the collision angle θ3 is set to be large to some extent (for example, “75 °”), the spray length can be made relatively short or relatively long by setting the air injection timing. For example, when fuel and air are injected at the same time, the air resistance between the spray and the airflow increases due to the backflow of the airflow generated at the time of the collision and the atomization of the spray. This action of increasing the air resistance overlaps with the collision between the fuel spray and the air jet, and the spray length becomes shorter than when no air is injected. On the contrary, when air is injected prior to the fuel, an air flow is generated in the direction in which the spray extends at the time of collision, so that the spray length becomes relatively long. However, it is known that the effect of changing the spray length in this case is smaller than that in the case where the collision angle θ3 is set to be small as described below.

  On the other hand, when the collision angle θ3 is set to be small (for example, “45 °”), the spray length can be relatively increased by setting the air injection timing. This is because the air jet collides with the fuel spray in the direction in which the fuel spray is pushed. When fuel and air are injected at the same time, the spray length becomes relatively long. When air is injected prior to the fuel, there is an air flow that becomes longer at the time of injection, so the spray length becomes even longer. In this case, since the variable amount of the spray length is larger than when the collision angle θ3 is set to be large, even if the basic fuel spray decreases the fuel pressure (for example, decreases from 12 MPa to 2 MPa), The deterioration of spray atomization due to the decrease in the fuel pressure can be improved by air blasting. Therefore, the spray length can be variably controlled by controlling the fuel spray and the air jet according to the fuel and air injection timing while the fuel pressure is reduced. For example, when fuel and air are simultaneously injected, the spray length can be made relatively long (shorter than when the fuel pressure is 12 MPa and no air blast is used). In addition, when air is injected prior to fuel, it becomes possible to further increase the spray length (it has been confirmed that the spray particle size can be made smaller than when the fuel pressure is 12 MPa and no air blast is used. .)

Here, with respect to the relationship between the collision angle θ3, the spray length, and the average spray particle size, experimental results as shown in FIG. 22 were obtained. In this experiment, the fuel injection device 3 shown in FIGS. 2 and 3 is used, the fuel (n-heptane) pressure is set to “12 MPa”, the air pressure of the air blast is set to “1 MPa”, and the fuel injection amount Is set to “9.18 * 10 ⁻³ (g / ms)”, the distance X from the fuel injection hole 69a to the air injection hole 69b is set to “1 mm”, and the air is set to the preceding injection by “1 ms” from the fuel. . Since it is the fuel injection device 3, the fuel injection hole 69 a has a circular cross-section, a size of “0.6 mm” inside diameter, a direction perpendicular to the end face of the orifice plate 69, and an arrangement of the orifice plate 69. Is set in the center of each. The number of air injection holes 69b is eight, the shape is circular in cross section (the opening end is an ellipse), the size is an inner diameter “1.0 mm”, and the direction is oblique to the end surface of the orifice plate 69. The arrangement with respect to the fuel injection hole 69a is set at equiangular intervals on the circumference centering on the fuel injection hole 69a. This setting is the same in the second and third embodiments.

  As is clear from FIG. 22, at the collision angle θ3 in the range of “15 to 75 °”, an effective spray length in the range of “105 to 82 mm” is obtained, and in the range of “8.5 to 7 μm”. It can be seen that an average spray particle size is obtained. The spray length when air injection was not performed under the above set conditions was “75 mm”.

  Therefore, in the first embodiment, the collision angle θ3 is set to a predetermined value in the range of “15 to 75 °”. Preferably, the collision angle θ3 is set to a predetermined value in the range of “15 to 45 °”. As a result, an effective spray length in the range of “105 to 93 mm” is obtained, and an effective average spray particle size in the range of “8.5 to 7.5 μm” is obtained. More preferably, the collision angle θ3 is set to a predetermined value in the range of “15 to 30 °”. As a result, an effective spray length in the range of “105 to 99 mm” is obtained, and an effective average spray particle size in the range of “8.5 to 8.0 μm” is obtained.

  Therefore, in the first embodiment, the collision angle θ3 is limited to a predetermined value in the range of “15 to 75 °”, so that the acting force of the air jet in the direction of the fuel spray is increased, and the spray length is further increased. It can be made longer. As a result, suitable fuel atomization can be achieved over the entire operating condition of the engine 1, and the spray length can be set appropriately.

<Example 2>
By setting the distance X from the fuel injection hole 69a to the air injection hole 69b described above, higher atomization and a longer spray length can be obtained with the same air pressure.

Here, experimental results as shown in FIG. 23 were obtained for the relationship between the distance X, the spray length, and the average spray particle size. In this experiment, the fuel injection device 3 shown in FIGS. 2 and 3 is used, the fuel (n-heptane) pressure is set to “12 MPa”, the air pressure of the air blast is set to “1 MPa”, and the fuel injection amount Was set to “9.18 * 10 ⁻³ (g / ms)”, the collision angle θ3 was set to “15 °”, and the air was set to the preceding injection by “1 ms” from the fuel.

  As is clear from FIG. 23, it can be seen that the smaller the distance X, the greater the effect of atomization of the spray and the extension of the spray length. Here, it has been found that just halving the distance X provides the same effect as doubling the air pressure. Therefore, by making the distance X as small as possible, it is possible to obtain spray atomization and the effect of extending the spray length with less energy. As can be seen from FIG. 23, the curve of the average spray particle diameter becomes slightly gentle when the distance X becomes “4 mm”. In the range of the distance X of “1 to 4 mm”, an effective spray length in the range of “105 to 95 mm” is obtained, and an effective average spray particle diameter of “about 9 μm” is obtained. Therefore, in the second embodiment, the distance X is set to a predetermined value in the range of “1 to 4 mm”. The spray length when air injection was not performed under the above set conditions was “75 mm”.

  Therefore, in the second embodiment, the distance X is limited to a predetermined value in the range of “1 to 4 mm”, so that the collision point HP between the air jet and the fuel spray is the optimum near the fuel injection hole 69a. Set to position. Thus, by setting the distance X in a limited manner, it is possible to increase the atomization of the fuel and extend the spray length by using the air jet of the same energy without changing the air pressure. As a result, suitable fuel atomization can be achieved over the entire operating condition of the engine 1, and the spray length can be set appropriately.

<Example 3>
By setting the fuel pressure supplied to the fuel injection valve 43 to a predetermined low pressure, the spray length can be varied without greatly changing the spray particle size (when the air collides with the fuel spray (with air) and the air collides. The difference in spray length (when no air is used) and no air) can be increased.

Here, with respect to the relationship between the fuel pressure and the spray length, an experimental result as shown in FIG. 24 was obtained. Moreover, the experimental result as shown in FIG. 25 was obtained about the relationship between a fuel pressure and an average spray particle size. In this experiment, the fuel injection device 3 shown in FIGS. 2 and 3 is used, the fuel is set to n-heptane, the air pressure of the air blast is set to “1 MPa”, and the fuel injection amount is set to “9.18 *”. 10 ⁻³ (g / ms) ”, the collision angle θ3 was set to“ 15 ° ”, and the air was set to the preceding injection by“ 1 ms ”from the fuel.

  As the required injection characteristics, it is desirable that the fuel pressure supplied to the fuel injection valve be lower for the spray particle size and the variable spray length from the viewpoint of the structure of the fuel injection valve and energy loss. Spray atomization by air blasting is possible with a small amount of energy, but in order to increase the spray length variable amount, a large amount of energy by air injection is required. Therefore, when the spray length variable amount is set so as to satisfy the required value, the spray particle size becomes smaller than the required value, and wasteful atomization energy is often used. In this case, by reducing the fuel pressure and increasing the particle size of the fuel spray itself that does not cause air to collide with the fuel spray, the fuel pressure can be lowered while satisfying the required values of the spray particle size and variable spray length. it can. In this case, by reducing the fuel pressure, the kinetic energy of the fuel spray itself becomes small, and the energy of the air jet becomes relatively large, so that the spray length variable amount becomes larger.

  As is clear from FIGS. 24 and 25, the atomization effect by air blast (with air) has a relationship that the average spray particle size is close to the -1/2 power with respect to the fuel pressure. It can also be seen that the spray length variable amount increases as the fuel pressure decreases. For this reason, in order to achieve both atomization and variable spray length using air brass, the most efficient fuel pressure from the viewpoint of energy consumption is the low pressure range where the spray length variable amount becomes large. It is better to set it in the range before the diameter changes. Therefore, in the third embodiment, the fuel pressure is set to a predetermined value in the range of “1 to 4 MPa”. Here, the particle size of the fuel spray has a relationship close to −½ power with respect to the fuel pressure. Further, by lowering the fuel pressure, the energy of the air jet is relatively increased with respect to the fuel spray. Therefore, by reducing the fuel pressure to a predetermined value in the range of “1 to 4 MPa” in a region where the particle size of the fuel spray does not change so much, only the spray length is achieved as necessary while achieving fuel atomization. It can be changed greatly. That is, the spray length change amount can be relatively increased without changing the average spray particle size so much. As a result, suitable fuel atomization can be achieved over the entire operating condition of the engine 1, and the spray length can be set appropriately.

[Second Embodiment]
Next, a second embodiment in which the direct injection fuel injection device of the present invention is embodied in a direct injection engine system will be described in detail with reference to the drawings.

  In the following embodiments including this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. Hereinafter, different points will be mainly described.

  This embodiment is different from the above embodiments in that the function of the air injection valve is provided integrally with the fuel injection valve. FIG. 26 shows a cross-sectional view of the air injection valve-integrated fuel injection valve 91. In the integrated fuel injection valve 91 of this embodiment, a cylindrical portion 55 a is integrally provided at the tip of the lower body 55. An orifice plate 85 is fixed to the tip of the cylindrical portion 55a. The lower body 55 is provided with an air passage 92 that opens to the cylindrical portion 55a. Pressurized air is supplied to the air passage 92 through an air pipe (not shown). Another solenoid 93 is provided at the base end of the lower body 55. The lower body 55 is provided with a valve body 94 that opens and closes the air passage 92. When the valve body 94 operates based on the excitation / demagnetization of the solenoid 93, the air passage 92 is opened and closed, pressurized air is supplied into the cylindrical portion 55a, and the pressure is applied from the air injection hole 85b of the orifice plate 85. Pressurized air is injected to form an air jet. Further, the fuel injected through the hole 66a of the tube 66 integrally provided at the center of the cylindrical portion 55a is injected from the fuel injection hole 85a of the orifice plate 85 to form a fuel spray.

  Also in this embodiment, as in Examples 1 to 3 in the first embodiment, the collision angle θ3 between the fuel spray and the air jet is limitedly set to a predetermined value in the range of “15 to 75 °”. The distance X from the center of the fuel injection hole 85a to the center of the air injection hole 85b is limited to a predetermined value in the range of “1 to 4 mm”, or the fuel pressure supplied to the fuel injection valve 91 is set to “1”. It may be limited to a predetermined value in a range of “˜4 MPa”.

  Therefore, in this embodiment, since the air injection valve-integrated fuel injection valve 91 is used, the fuel injection device is configured more compactly than the respective embodiments in which the fuel injection valve 43 and the air injection valve 44 are separately provided. can do. Other functions and effects in this embodiment are basically the same as those in the above embodiments.

[Third Embodiment]
Next, a third embodiment in which the direct injection fuel injection device of the present invention is embodied in a direct injection engine system will be described in detail with reference to the drawings.

  This embodiment is different from the above embodiments in that the fuel injection valve is provided with the injection function of the air injection valve. FIG. 27 shows a cross-sectional view of the fuel injection valve 95. In the fuel injection valve 95 of this embodiment, the lower body is provided integrally with the housing 51. An orifice plate 85 is directly fixed to the tip of the housing 51. A fuel passage 96 that communicates between the fuel injection hole 85 a of the orifice plate 85 and the valve hole 56 b of the nozzle body 56 is provided at the distal end portion of the housing 51. Similarly, an air passage 97 is provided around the fuel passage 96 at the tip of the housing 51. Pressurized air is supplied to the air passage 97 through a separate air control valve (not shown). By controlling the air control valve, the pressurized air is injected from the air injection hole 85b of the orifice plate 85 through the air passage 97, and an air jet is formed. Further, when the valve portion 58a is opened and closed with respect to the valve seat 56a, fuel is injected through the fuel passage 96 and the fuel injection hole 95a of the orifice plate 85 to form fuel spray.

  Also in this embodiment, as in Examples 1 to 3 in the first embodiment, the collision angle θ3 between the fuel spray and the air jet is limitedly set to a predetermined value in the range of “15 to 75 °”. The distance X from the center of the fuel injection hole 85a to the center of the air injection hole 85b is limited to a predetermined value in the range of “1 to 4 mm”, or the fuel pressure supplied to the fuel injection valve 95 is set to “1”. It may be limited to a predetermined value in a range of “˜4 MPa”.

  Therefore, in this embodiment, since the function of the air injection valve is provided in the fuel injection valve 95, the engine relating to the fuel injection device is compared with each of the embodiments in which the fuel injection valve 43 and the air injection valve 44 are provided separately. The surrounding configuration can be made compact. Other functions and effects in this embodiment are basically the same as those in the above embodiments.

[Fourth Embodiment]
Next, a fourth embodiment in which the direct injection fuel injection device of the present invention is embodied in a direct injection engine system will be described in detail with reference to the drawings.

  The fuel injection device according to this embodiment includes the fuel injection valve for forming one fuel spray and the plurality of air injection valves for individually forming the plurality of air jets. The configuration is different from that of the fuel injection valve.

  FIG. 28 shows a cross-sectional view of the schematic configuration of the fuel injection device. The fuel injection valve 43 and the two air injection valves 44 have the same basic configuration. The detailed configuration of these injection valves 43 and 44 is the same as that of the fuel injection valve 43 shown in FIG. In this embodiment, the configuration of the fuel injection hole 101 provided corresponding to the fuel injection valve 43 and opening to the combustion chamber 2 may be, for example, a circle or a slit-like rectangle. On the other hand, the air injection holes 102 provided corresponding to the air injection valves 44 and opening to the combustion chamber 2 may be formed by arranging a plurality of circular air injection holes in a line, and having a rectangular shape. It may be an air nozzle hole. Also in this embodiment, the air jet having the same size and intensity distribution as the fuel spray is set to collide with the fuel spray at the collision point HP. As described above, this fuel injection device is configured to cause the fuel injected from the fuel injection valve 43 and the air injected from each air injection valve 44 to collide in the combustion chamber 2.

  Also in this embodiment, as in Examples 1 and 3 in the first embodiment, the collision angle θ3 between the fuel spray and the air jet is limitedly set to a predetermined value in the range of “15 to 75 °”. Alternatively, the fuel pressure supplied to the fuel injection valve 43 may be limited to a predetermined value in the range of “1 to 4 MPa”.

  Therefore, also in the fuel injection device of this embodiment, functionally, the same operation effect as the fuel injection device of each of the above embodiments can be obtained.

[Fifth Embodiment]
Next, a fifth embodiment in which the direct injection fuel injection device of the present invention is embodied in a direct injection engine system will be described in detail with reference to the drawings.

  The fuel injection device of this embodiment is a modification of the second embodiment. FIG. 29 is a sectional view showing a schematic configuration of this fuel injection device. As can be seen from the comparison with FIG. 26, the integrated fuel injection valve 98 is configured to cause the air jet to collide with the fuel spray only from one side. The integral fuel injection valve 98 basically has the same configuration as the integral fuel injection valve 91 in the second embodiment. Therefore, the detailed description of the injection valve 98 is omitted. In this embodiment, the fuel injection hole 85a forms a slit-like rectangle, and the air injection hole 85b forms a rectangle. Then, an air jet is generated from the air nozzle 85b located on one side of the fuel nozzle 85a. Further, an air jet having the same size and intensity distribution as the fuel spray is set to collide with the fuel spray at the collision point HP. As described above, this fuel injection device is configured to cause the fuel injected from the integral fuel injection valve 98 to collide with the air injected from the air injection hole 85b in the combustion chamber 2.

  Also in this embodiment, as in Examples 1 to 3 in the first embodiment, the collision angle θ3 between the fuel spray and the air jet is limitedly set to a predetermined value in the range of “15 to 75 °”. The distance X from the center of the fuel injection hole 85a to the center of the air injection hole 85b is limited to a predetermined value in the range of “1 to 4 mm”, or the fuel pressure supplied to the fuel injection valve 98 is “1”. It may be limited to a predetermined value in a range of “˜4 MPa”.

  Therefore, also in the fuel injection device of this embodiment, functionally, the same operation effect as the fuel injection device of each of the above embodiments can be obtained. In addition, in this embodiment, since the air injection holes 85b are arranged only on one side of the fuel injection holes 85a to generate the air jets, as shown in FIG. 29, the direction of the fuel spray by the collision of the air jets Can be changed diagonally in the horizontal direction. For this reason, the fuel can be atomized in accordance with the shape of the combustion chamber 2.

[Sixth Embodiment]
Next, a sixth embodiment in which the direct injection fuel injection device of the present invention is embodied in a direct injection engine system will be described in detail with reference to the drawings.

  In the fuel injection device of this embodiment, the function of the fuel injection device in the second embodiment is achieved not by the integral fuel injection valve 98 but by the fuel injection valve 43 and the air injection valve 44 provided separately. To do. FIG. 30 is a sectional view showing a schematic configuration of the fuel injection device. As can be seen from comparison with FIG. 29, in this embodiment, one fuel injection valve 43 and at least one air injection valve 44 are assembled to the cylinder head 46. In this embodiment, the configuration of the fuel injection hole 101 provided corresponding to the fuel injection valve 43 and opening to the combustion chamber 2 may be, for example, a circle or a slit-like rectangle. On the other hand, the air injection holes 102 provided corresponding to the air injection valves 44 and opening to the combustion chamber 2 may be formed by arranging a plurality of circular air injection holes in a line, and having a rectangular shape. It may be an air nozzle hole. And the air injection valve 44 is arrange | positioned so that an air jet may collide only with respect to the fuel spray from one fuel injection valve 43 from one side. That is, the jet axis AL of the air jet from the air nozzle hole 102 is set to intersect at the collision point HP at the maximum diameter of the fuel spray from the fuel injection valve 43. As described above, this fuel injection device is configured to cause the fuel injected from the fuel injection valve 43 and the air injected from the air injection valve 44 to collide in the combustion chamber 2.

  Also in this embodiment, as in Examples 1 and 3 in the first embodiment, the collision angle θ3 between the fuel spray and the air jet is limitedly set to a predetermined value in the range of “15 to 75 °”. Alternatively, the fuel pressure supplied to the fuel injection valve 43 may be limited to a predetermined value in the range of “1 to 4 MPa”.

  Therefore, also in the fuel injection device of this embodiment, functionally, the same operation effect as the fuel injection device of each of the above embodiments can be obtained. In addition, in this embodiment, since the air injection valve 44 is disposed only on one side of the fuel injection valve 43 to generate the air jet, as shown in FIG. 30, the direction of the fuel spray is caused by the collision of the air jet. Can be changed diagonally in the horizontal direction. For this reason, the fuel can be atomized in accordance with the shape of the combustion chamber 2.

[Seventh Embodiment]
Next, a seventh embodiment in which the direct injection fuel injection device of the present invention is embodied in a direct injection engine system will be described in detail with reference to the drawings.

  31 to 33 are sectional views showing a schematic configuration of the fuel injection device according to this embodiment. In the fuel injection device of this embodiment, at least first and second air injection valves 44 </ b> A and 44 </ b> B are provided for one fuel injection valve 43 including one fuel injection hole 101. An air injection hole 102 is provided corresponding to each air injection valve 44A, 44B, and the use of each air injection valve 44A, 44B is switched in order to selectively switch the injection of air from each air injection hole 102. Configured.

  In this embodiment, the first and second air injection valves 44 </ b> A and 44 </ b> B are arranged so that an air jet collides only with one side of the fuel spray formed by one fuel injection valve 43. That is, the air jet injected from the air injection hole 102 of the first air injection valve 44A having the same size and intensity distribution as the fuel spray at the collision point HP is set to collide with the fuel spray. Similarly, the air jet flow injected from the air injection hole 102 of the second air injection valve 44B having the same size and intensity distribution as the fuel spray at the collision point HP is set to collide with the fuel spray. As described above, this fuel injection device is configured to cause the fuel injected from the fuel injection valve 43 to collide with the air injected from the air injection valves 44A and 44B in the combustion chamber 2. .

  Further, in this embodiment as well, as in Examples 1 and 3 in the first embodiment, the collision angle θ3 between the fuel spray and the air jet is limitedly set to a predetermined value in the range of “15 to 75 °”. Alternatively, the fuel pressure supplied to the fuel injection valve 43 may be limited to a predetermined value in the range of “1 to 4 MPa”.

  Therefore, also in the fuel injection device of this embodiment, functionally, the same operation effect as the fuel injection device of each of the above embodiments can be obtained. In addition, according to the fuel injection device of this embodiment, the injection of air from each air injection hole 102 is selectively switched by switching the use of the two air injection valves 44A and 44B. Therefore, by this switching, the form of collision of the air jet against the fuel spray is changed, and the shape of the fuel spray is changed. That is, as shown in FIG. 32, when only the first air injection valve 44A is selectively used for the fuel injection valve 43, it is relatively narrow when the air jet collides with the fuel spray. Collisions can occur in range. On the other hand, as shown in FIG. 33, when only the second air injection valve 44B is selectively used for the fuel injection valve 43, it is relatively wide when the air jet collides with the fuel spray. Collisions can occur in range. Thus, the size of the collision range between the fuel spray and the air jet can be switched between two types. As a result, the spray length and spray shape can be selectively switched and used, and fuel atomization can be adjusted in accordance with the operating conditions of the engine 1.

  The present invention is not limited to the embodiments described above, and can be implemented as follows by appropriately changing a part of the configuration without departing from the spirit of the invention.

  (1) In each of the above embodiments, air (air) is used as the gas that collides with the fuel. However, a specific gas other than air may be used.

  (2) In the first embodiment, in Examples 1 to 3, the shape, size, orientation, and arrangement of the fuel injection holes 69a and the number, shape, size, orientation, and fuel injection holes 69b are provided. Although the arrangement with respect to 69a is specified and set to a predetermined value, the specification of these components is not limited to the above-described predetermined value, and may be appropriately changed within a practicable range.

  (3) In each of the above embodiments, a limited setting related to the collision angle θ3 between the fuel spray and the air jet, a limited setting related to the distance X from the center of the fuel nozzle hole to the center of the air nozzle hole, The limited setting related to the fuel pressure supplied to the fuel injection valve may be set in an appropriate combination in one fuel injection device.

  Specifically, the collision angle θ3 between the fuel spray and the air jet is set to a limited setting in which the distance X from the center of the fuel nozzle hole to the center of the air nozzle hole is set to a predetermined value in the range of “1 to 4 mm”. In combination with a limited setting of a predetermined value in the range of “15 to 75 °”, or a limited setting of setting the fuel pressure supplied to the fuel injection valve to a predetermined value in the range of “1 to 4 MPa” A limited setting that sets the collision angle θ3 to a predetermined value in the range of “15 to 75 °” may be combined. In any of these cases, the acting force of the air jet in the direction of fuel spray becomes large, and the spray length can be made longer.

  The distance X is limited to a predetermined value in the range of “1 to 4 mm”, and the fuel pressure supplied to the fuel injection valve is limited to a predetermined value in the range of “1 to 4 MPa”. May be combined. In this case, the fuel pressure decreases in a region where the particle size of the fuel spray does not change so much, and the change rate of the spray length can be relatively increased.

  Further, the distance X is limited to a predetermined value within a range of “1 to 4 mm”, the collision angle θ3 is limited to a predetermined value within a range of “15 to 75 °”, and fuel injection is performed. You may combine with the limited setting which makes the fuel pressure supplied to a valve the predetermined value of the range of "1-4 Mpa". In this case, the spray length can be made longer, and the change rate of the spray length can be relatively increased.

1 is a schematic configuration diagram showing a direct injection engine system. Sectional drawing which shows the engine attachment state of a fuel-injection apparatus. FIG. 2 is a conceptual diagram showing a configuration of electrical wiring and the like related to a fuel injection valve and an air injection valve. The expanded sectional view which shows the front-end | tip part of an attachment member. The top view which shows an orifice plate. AA line sectional view of Drawing 5. (a)-(c) is a conceptual diagram which shows fuel spray and an air jet. The conceptual diagram which shows the collision with the fuel spray and gas jet at a collision point. The conceptual diagram which shows a gas jet. (a)-(c) is a conceptual diagram which shows the difference of the spray strength and jet strength at a collision point. The conceptual diagram when an air jet collides with fuel spray. The flowchart which shows a fuel-injection control routine. The table | surface which shows the relationship between an engine operating state, a combustion pattern, etc. (a), (b) is a time chart which shows the opening / closing timing of a fuel injection valve and an air injection valve. (a), (b) is a time chart which shows the opening / closing timing of a fuel injection valve and an air injection valve. (a), (b) is a time chart which shows the opening / closing timing of a fuel injection valve and an air injection valve. The image figure which shows the spray characteristic of warm-up combustion. The image figure which shows the spraying characteristic of stratified combustion. The image figure which shows the spraying characteristic of uniform combustion. (a)-(c) is explanatory drawing which shows the difference in the penetration distance of fuel spray. The conceptual diagram when an air jet collides with fuel spray. The graph which shows the relationship between a collision angle, spray length, and an average spray particle size. The graph which shows the relationship between the distance X, spray length, and average spray particle diameter. The graph which shows the relationship between fuel pressure and spray length. The graph which shows the relationship between a fuel pressure and an average spray particle size. Sectional drawing which shows an integrated fuel injection valve. Sectional drawing which shows a fuel injection valve. Sectional drawing which shows schematic structure of a fuel-injection apparatus. Sectional drawing which shows schematic structure of a fuel-injection apparatus. Sectional drawing which shows schematic structure of a fuel-injection apparatus. Sectional drawing which shows schematic structure of a fuel-injection apparatus. Sectional drawing which shows schematic structure of a fuel-injection apparatus. Sectional drawing which shows schematic structure of a fuel-injection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Combustion chamber 3 Fuel injection apparatus 14 Intake valve 15 Exhaust valve 43 Fuel injection valve 44 Air injection valve 69a Fuel injection hole 69b Air injection hole 85a Fuel injection hole 85b Air injection hole 91 Air injection valve integrated fuel injection valve 95 Fuel Injection valve 98 Integrated fuel injection valve 101 Fuel injection hole 102 Air injection hole θ3 Collision angle X Distance

Claims (6)

A direct injection fuel injection apparatus comprising a fuel injection valve for injecting fuel into a combustion chamber of an internal combustion engine including an intake valve and an exhaust valve, and a gas injection valve for injecting gas into the combustion chamber. ,
Including one fuel injection valve, and corresponding to the fuel injection valve, provided with one or more fuel injection holes opened in the combustion chamber;
Including at least one gas injection valve, and corresponding to the gas injection valve, provided with one or more gas injection holes opened in the combustion chamber;
Identifying the shape, size, orientation and arrangement of the fuel nozzle holes;
The number, shape, size, orientation, and arrangement of the gas nozzle holes are specified;
A distance from the center of the fuel injection hole to the center of the gas injection hole is set to a predetermined value in a range of 1 to 4 mm, and is injected from the fuel injection valve and passes through the fuel injection hole. A direct injection type fuel injection apparatus configured to collide fuel injected into the gas and gas injected from the gas injection valve and injected into the combustion chamber through the gas injection hole. A direct injection fuel injection apparatus comprising a fuel injection valve for injecting fuel into a combustion chamber of an internal combustion engine including an intake valve and an exhaust valve, and a gas injection valve for injecting gas into the combustion chamber. ,
Including one fuel injection valve, and corresponding to the fuel injection valve, provided with one or more fuel injection holes opened in the combustion chamber;
Including at least one gas injection valve, and corresponding to the gas injection valve, provided with one or more gas injection holes opened in the combustion chamber;
Identifying the shape, size, orientation and arrangement of the fuel nozzle holes;
The number of the gas injection holes, the shape, the size, the direction, and the arrangement with respect to the fuel injection holes are specified, and the fuel injected from the fuel injection valve and injected into the combustion chamber through the fuel injection holes And a gas injected from the gas injection valve and injected into the combustion chamber through the gas injection hole, and a fuel injected from the fuel injection hole and an injection from the gas injection hole A direct injection type fuel injection device, wherein a collision angle with gas is set to a predetermined value in a range of 15 to 75 °. A direct injection fuel injection apparatus comprising a fuel injection valve for injecting fuel into a combustion chamber of an internal combustion engine including an intake valve and an exhaust valve, and a gas injection valve for injecting gas into the combustion chamber. ,
Including one fuel injection valve, and corresponding to the fuel injection valve, provided with one or more fuel injection holes opened in the combustion chamber;
Including at least one gas injection valve, and corresponding to the gas injection valve, provided with one or more gas injection holes opened in the combustion chamber;
Identifying the shape, size, orientation and arrangement of the fuel nozzle holes;
The number, shape, size, orientation, and arrangement of the gas nozzle holes are specified;
Fuel pressure injected from the fuel injection valve is set to a predetermined value in a range of 1 to 4 MPa, and is injected from the fuel injection valve and injected into the combustion chamber through the fuel injection hole And a gas injected from the gas injection valve and injected into the combustion chamber through the gas injection hole. The collision angle between the fuel injected from the fuel injection hole and the gas injected from the gas injection hole is set to a predetermined value in a range of 15 to 75 °. Direct injection type fuel injection device. The direct injection type fuel injection device according to claim 1, wherein the pressure of the fuel injected from the fuel injection valve is set to a predetermined value in a range of 1 to 4 MPa. The collision angle between the fuel injected from the fuel injection hole and the gas injected from the gas injection hole is set to a predetermined value in a range of 15 to 75 °;
2. The direct injection type fuel injection device according to claim 1, wherein the pressure of the fuel injected from the fuel injection valve is set to a predetermined value in a range of 1 to 4 MPa.

Images